(Read March 19th, 1903).


As is well known, the Yorkshire Wolds, composed in part of flinty and of flintless chalk, extend in the form of a rough crescent from Flambrough [sic] Head to the Humber. The general dip of the Chalk is to the south-east, swinging more to the east before it reaches the coast, and the general slope of the upland is in the same direction, so that the higher parts of the Chalk country are along the escarpments which overlook the Vale of York to the west, and the Vale of Picketing to the north. To the south-east the Wolds sink gradually beneath the Glacial Drift which covers Holderness, and the surface of the Chalk in this quarter is considerably below sea-level.

 It must be noted, however, that the glacial deposits so abundant in Holderness and the east coast generally, do not extend to the higher parts of the Chalk wolds, and that though the drift which covers their south-eastern flanks rises in some places to a considerable height, there is a large area of high land to the north and xvest entirely free from recognisable glacial deposits, and this area has been mapped as driftless by the officers of the Geological Survey. But on these high level areas, in spite of the absence of glacial drift, it has been found that quartzite pebbles occur in large numbers. The pebbles vary greatly in size, but probably their average diameter is from two to three inches. In colour they vary from a dull yellow to a yellowish red. They are well rounded, and in this respect resemble the Bunter pebbles so abundant in the Midland counties. These pebbles are also generally accompanied by pebbles of a hard reddish sandstone, somewhat larger than the quartzites, but fewer in number and apparently not so waterworn. The scanty soil of the Wolds is of course highly charged with fragments of chalk and flint, but the pebbles in question can be distinguished from this local material at a glance.

 It has not yet been ascertained whether the pebbles occur over the whole of the western parts of the Wolds, but judging from the areas in the neighbourhood of Riplingham, Bush Hill, High Hunsley, Hessleskew, Millington, East Luton, and other localities which have already been under observation, the general conditions of their occurrence seems to be as follows:--

   (1) The pebbles occur at high levels, generally from 400 feet to 500 feet above sea level, near the western escarpment of the Wolds.

 (2) They are scattered unevenly over the fields, sometimes few and far between, at other times averaging as many as six pebbles to the square foot.

 (3) The pebbles are rare on the sides of the dales, but are the most plentiful on the high level (flat) lands which .intervene between the dales; the rule being the flatter the land the more numerous the pebbles.

 (4) They also occur, as the only foreign pebbles, in the chalk gravels which underlie the boulder clay at Hessle, and they are also recorded from the old chalk breccias, Fairy Stones, &c., of the higher Wolds.

 In seeking for an explanation of the presence of these scattered pebbles on the high Chalk wood it may be pointed out that (1) no local rocks occur in situ from which the pebbles can have been derived; that (2) the pebbles being limited to quartzites and sandstones, cannot have come from the Glacial Drift to the east of the Wolds, because these drifts are famous for the immense variety of rocks represented amongst their boulders and pebbles ; that (3) for similar reasons, neither can the pebbles be correlated with the gravels of the Vale of York

 In writing to ask the opinion of my friend Mr. G. W. Lamplugh some time ago with regard to these interesting strangers, I received in reply a letter from which the following sentences are, with his permission, reproduced :--

 "I cannot even offer an opinion as to what your quartzite drift on the top of the Wolds may be. It may be well, however, to remind you of the 'Lenham Beds' of Pliocene age that occur in scraps on the north Downs. Relics of this kind might persist on the surface of the Wolds where protected from glaciation even though a considerable thickness of the underlying chalk had disappeared in solution. As the result of work in other places since leaving York- shire, I do not feel so confident that the Wolds remained ice-free throughout the Glacial period. It is clear that they were not overswept by the ice at the time that the Speeton moraine was formed, nor at any later stage. But if evidence be found to indicate that they were covered at an earlier period, I should take it very carefully into consideration. Still, your materials scarcely suggest an ice-covering, either from the west or east. You are working on interesting lines, and I advise you to continue."

 It would indeed be interesting if these quartz pebbles should be the only surviving relics of some Pliocene or at any rate Pre-glacial deposits hitherto unrecognised in Yorkshire. But at present the evidence is too slight to bear the weight of such a conclusion.

 It may be remarked that in some high level gravels of uncertain age in the south of England, beyond the limits of the Great Glaciation, quartzite pebbles also occur, and have given rise to much speculation.

In conclusion, the writer of these notes would like to acknowledge the invaluable help he has received from Mr. G. W. B. Macturk, both in the field and many other ways.



[Note -This article has been scanned in from original printed format and then put through an OCR program by Mike Horne. The process may have introduced some new spelling errors to the texts. Some original misspellings have been corrected.]

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